More Corn On Corn?

Michele Holtkamp-Frye | Dec 01, 2006

Mike Shuter has one eye on burgeoning ethanol plants and the other on his business plan for shifting to more corn acreage. This year, he made the shift.

Shuter, who farms with his father and sons Brian and Patrick northeast of Indianapolis, IN, now devotes two-thirds of his 3,200-acre farm to corn, with the remaining one-third planted to soybeans. In previous years, they had a 50-50 split.

About 500 acres on the farm are in the first year of a corn-corn rotation. In the spring, 1,000 acres will be planted corn back to corn.

Shifting to a continuous corn rotation requires more intensive field scouting and higher start-up costs, experts say. These costs are, it's hoped, offset by higher corn prices, driven in turn by sharp demand for 5-6 million more acres of corn next year to feed ethanol plants. This translates to a shortage of 300-400 million more bushels of corn needed every year, says Matt Roberts, Ohio State agricultural economist.

The economic feasibility of continuous corn was recently analyzed by Purdue University Agricultural Economists Bruce Erickson and Jess Lowenberg-DeBoer. They found that a 3,000-acre farm in the Eastern Corn Belt with average rotational per-acre yields of 176 bu. for corn and 57 bu. for soybeans would have to produce at least 225 bu. an acre in continuous corn to meet higher costs and still earn a profit.

Shifting to corn on corn is made easier today than it would have been a decade or two ago by advances in genetics and seed treatments, Roberts says.

So Shuter and family made what he calls a big-picture shift in philosophy. Here's how they did it.

In anticipation of the shift, they leased a John Deere 9760 combine with a 12-row head to see how the rest of the system would handle an increased amount of corn.

Over the summer, they built a 60,000-bu. grain bin and a 6,000 bu./hour leg for a wet dump drying system.

It's worked, Shuter says. On an October day, harvesting six miles from the grain setup, three semis were able to keep up with the 12-row corn head with 175-180 bu. yields.

The yields on the continuous corn are consistent with the corn that was planted on soybean ground, Shuter says.

That didn't happen by chance. Several deliberate steps are being taken to keep corn yields high.

The ground has been no-tilled for 15 years. Shuter is strip-tilling in between the rows and planting right back on the row and sidedressing it.

Organisms and earthworms, according to agronomists, are breaking down corn stalks that have been no-tilled for several years.

Strip-tilling and precision fertilizing gets the seed off to a strong start.

The early spring environment of planting corn back to corn can sometimes be challenging since corn produces more residue than soybeans, Purdue's Erickson says. Rougher seedbeds may mean less accurate planting depths, and furrow opening and closing may not be as complete, he adds. Along with the cooling and wetting effect of the residue, the early environment for corn on corn can be a greater challenge.

“That is where a system like Mike Shuter uses is beautiful,” Erickson says. Shuter tills a narrow strip of ground in the fall, applies fertilizer, and then plants right in that narrow strip using global-positioning systems the following spring. So between the rows, he has the soil and water conservation benefits of no-till.

Corn on corn responds better to more management, more nitrogen, more fertilizer, better seeds and more tillage. Many growers may have to consider more tillage if they go to a corn-corn rotation, Erickson says.

It takes tillage to get the best yields, but Shuter is able to get around that by using strip-till with auto guidance.

“We're talking about maybe $30 an acre more in nitrogen,” says Purdue's Lowenberg-DeBoer. “Fall tillage might cost another $20 an acre or so. All of this adds up to — for the high-yield continuous system — costing somewhere between $80 and $100 more an acre,”the Purdue team concludes.

The biggest risk for farmers taking even an intermediate step to a corn-corn-bean rotation is crop disease, Roberts says.

Leaf diseases are a bigger threat in corn-corn because of the amount of residue remaining after harvest, says Erickson.

The environment for weeds changes as well, with only half of the weed-control options for a full rotation, he adds.

The increase in residue leaves fewer options for weed control, and soil-applied herbicides can be less effective, he says.

Corn rootworm has historically been one of the biggest reasons to rotate crops. Insecticide options have helped control that.

Shuter has switched to a triple-stack corn, which Roberts thinks will become much more common as farmers shift to more continuous corn.

Some growers may be more interested in a corn-corn rotation because of a corn rootworm variant that causes farmers as many rootworm problems in a corn-bean rotation as they have in corn back to corn, Erickson says.

The most difficult years for a corn back to corn operation are years two and three. Most agronomic research points to a 10% yield penalty when corn follows corn, he says. Over time, the yield penalty diminishes if farmers stick with corn in the same field. Some growers are moving to a corn-corn-bean rotation. Other growers don't believe that corn following corn brings on a yield penalty or believe that they can overcome it, Erickson says.

He suggests growers consider these factors:

Corn after corn has a better advantage in some of the highest-yielding environments. So plant corn back to corn in the best fields.

The heart of the Corn Belt has higher-yielding land, so expect to see more farmers there shift crop rotations than farmers on the fringe.

Corn is more sensitive to planting dates than soybeans.

New machinery is one of the biggest expenses associated with continuous corn because most growers already use their equipment as intensively as possible, Roberts says.

Besides machinery, increased corn production requires more bin space, more drying systems and higher trucking costs. “If you can handle those four, the rest will take care of itself,” Roberts says.

Corn will produce three times the amount of grain as beans at harvest time, so farmers also need to consider, like Shuter did, having more trucking, combine and drying capacity, Erickson says.

“This can really change the whole plan for a big farmer,” he adds. “These things can prompt a cascade of management decisions.”

The lease program on the combine is working for Shuter. The farm owns the grain head and corn head, but the dealer has to store the combine and take care of the repairs. However, he's never waited more than an hour for repairs.

Like Shuter, most farmers aren't expecting to move to continuous corn for one or two years. “They want that to be a rotation they can use for 5, 10 or 15 years,” Roberts says. “I think that's a very common attitude.” He hopes they don't sacrifice too much profit in the first few years of a shift. He just wants them to be aware of all that could happen.